Alias for Ext.ComponentQuery.query()

Ext.ComponentQuery.query() is an amazingly powerful and useful function. I've been using it all over the place. The only problem with it is that it's a pretty long name for something that's used so often - in jQuery, for example, a roughly analogous function is aliased to $() for convenience.

So, since I couldn't find anything in PR3 regarding an alias for this function, I created my own: